Papilla response of barley epidermal cells caused by Erysiphe graminis: rate and method of deposition determined by microcinematography and transmission electron microscopy

Abstract

ZEYEN, R. J.. ;111d W. R. BUSHNELL. 1979. response of barley epidermal cells causecl by Et:~,.si/~hr gr~trri~irri.~: I-ate and method of deposition determined by rnicrocinemutogfi~phy and tr':~nsmission electron mic~'oscopy. Can. J. Bot. 57: 898-913. Papillae were cleposited in barley epitle~mal cells directly heneath appressoria of Et:vsiplrt, gt.o/irirli.c f. sp. Irordri anti appeal-ed as hemispherical, intel-nal wall appositions. The papilla {response began shortly after the formation of a ~.apitlly moving cytopl:~smic ;tggl.egate beneath the appressorium. As tlocumentetl in coleoptile tissue hy time-lapse light microcinematogl-aphy, the papillae grew ~xpitlly for 20-30min after becoming visible, their-I-atlii increasing by 0. I l~mlmin. For small papillae. tleposition continued for about 30rnin; for larger papillae, deposition continuetl for 120-180min. R e s~~l t s with tl'ansmission electron microscopy on leaf epidermal cells s~~ggested that papilla deposition by host cytoplasmic aggregates can be divided into ~O L I I .sequenti211 stages: (i) the tleposition of osrniophilic (lipidic) m:~te~.i:~ls. (ii) the deposition and partiill compaction of nonosmiophilic, amorphous material (probably insol~~ble polysaccharitles). (iii) compaction of nonosmiophilic, 21mo1-phous material, and (iv) the incorpo~.ation of osmiophilic material into the host wall and into the compacted nonosmiophilic, amorphous material. At maturity, the papillae are h:~rtlenecl, electron-opaque wall appositions that may be effective in preventing fungal penetration iuitl development. Failure of papillae to prevent fungal penetration and development may be related to the inability of the epidermal cells to complete the entire sequence of events in papilla deposition befol-e attempted fungal penetration. Z E Y E N ,R. J., et W. R. BUSHNELI.. 1979. Papilla response of barley epidermal cells caused by Ery.si/~l~e grtrrr~ir~is: rate and method of deposition determined by microcinematography and transmission electron microscopy. Can. J. Bot. 57: 898-913. Dans les cellules epidermiques de I'orge, les papilles se deposent dil-ectement SOLIS I'appressorium de I'B?;siphc grtrtni~~is f.sp. I~ortlri, et apparaissent SOLIS forme d'appositions parietales internes hemispheriq~~es. La reaction papillaire commence peu de temps aprts la formation d '~~n itgre~it cytoplasmique i mouvement rapide SOLIS I'appressorium. Sur des tiss~ls de coleoptiles e t~~d~e s par la microcinematoglaphie intermittente, on constate que les papilles croissent ~xpide-ment pendant 20-30 min apses l e~~r apparition alors que leur rayon augmente de 0. I pmlmin. La deposition continue pendant environ 30 min P O L I~ les petites papilles et 120-180 min pour les grosses. En microscopie electronique par t~xnsmission, I'observation de cellules epidermiques foliaires indique que la deposition de la papille par les agregats cytoplasmiques de I'hbte peut etre divisee en quatre stades successifs: (i) la deposition de materiaux osmiophiles (lipidiques), (ii) la tleposition et la compaction pa...

The PEN1 Syntaxin Defines a Novel Cellular Compartment upon Fungal Attack and Is Required for the Timely Assembly of Papillae

“…This compartment was seen to accumulate in the vicinity of papillae. We speculate that this PEN1-related compartment might correspond to the "large vesicles" described previously in the defense literature (Zeyen and Bushnell, 1979;Hü ckelhoven et al, 1999) and that PEN1 might mediate its fusion at infection sites during papilla formation.…”

“…The latter possibility, though unexpected, is consistent with the observation of GFP-PEN1 fluorescence in the apparent interior of the papillar structure. Unusual trafficking and fusion events, involving the fusion of unusually large "vesicles" 1 m in diameter at the papillae, have been reported during papilla formation (Zeyen and Bushnell, 1979), and such compartments have been shown to target reactive oxygen species toward infection sites (Hü ckelhoven et al, 1999). Collins et al (2003) report a decrease in the number of large vesicles observed at sites of failed penetration by the fungus in pen1 mutants.…”

“…This suggests that the nonhost barley powdery mildew exerts a mechanical force on the plant cell wall and that it also has the ability to enzymatically digest the wall (compare to Howard andValent, 1996 andBushnell, 1979).…”

Ultrastructural and histochemical studies on interactions between Vitis vinifera L. and Uncinula necator (Schw.) Burr.

“…Near the contact area various modifications of the cell walls ('altered walls', 'haloes' and autofluorescence) have been observed (Ride & Pearce, 1979;Koga, Mayama & Shishiyama, 1980;Aist & Israel, 1986;Heath & Stumpf, 1986;Parry & Carver, 1986). Ultrastructural observations reveal an enhanced electron contrast in these regions (Kunoh et al, 1979;Zeyen & Bushnell, 1979). Material is often deposited at the inner side of the external cell wall at the site of infection, forming a so-called papilla which can be induced even before the fungus penetrates (Stanbridge, Gay & Wood, 1971;McKeen & Rimmer, 1973;Aist & Israel, 1977) and is associated with a cytoplasmic aggregation at the interface site (Heath, 1980; Stolzenburg, Aist & Israel, 1984).…”

Ultrastructure of the Interface between Erysiphe pisi and Its Nonhost Plant, Barley.

“…Thus, it is likely that a rapid fusion of the membrane of spherosomes to the plasmalemma allows for the osmiophilic contents of the vesicles to be deposited into the developing papilla. This would result in papilla enlargement within 20-30min after the initiation of cytoplasmic aggregation2, 5,8,20). Zeyen and Bushnell20) observed papilla formation in living barley coleoptiles inoculated with E. graminis and reported that papillae were deposited rapidly for an initial 20-min period after initiation of cytoplasmic aggregation, by which time they had attained 80% of their final area, and they showed little growth after the first 30min.…”